Position detection systems and methods

ABSTRACT

A system for detecting a position of a dual solenoid device includes device configured to move between first and second positions, and a controller. The controller has first and second monitoring circuits in operable communication with first and second channels, respectively. The first and second channels are in operable communication with first and second solenoids, respectively. Each solenoid is configured to selectively operate as an active solenoid to move the device when the solenoid and its respective channel are in an active mode, and as a passive solenoid when the solenoid and its respective channel are in a passive mode to passively move with the active solenoid. Each of the monitoring circuits is configured to determine a position of the device when the channel the monitoring circuit is associated with is operating in the passive mode by monitoring an electrical parameter of the passive solenoid associated with that channel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is continuation application of U.S. patent applicationSer. No. 15/487,819, filed Apr. 14, 2017, the contents of which areincorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The subject disclosure relates to solenoid valves or actuators, inparticular systems and methods for detecting the position of a dualsolenoid valve or actuator.

2. Description of Related Art

Many aerospace applications utilize solenoids for actuators or valves.Independent measurements of actuator/valve position are sometimes taken.Traditionally, this measurement is taken with a dedicated sensor orswitch that indicates the position of the valve/actuator. This extrasensor or switch tends to add additional system cost and weight and alsotends to add additional electrical harnessing in the aircraft.Additionally, for many flight critical systems, the solenoid actuator orvalve may be dual channel for additional redundancy. Often, only onechannel (the active channel) will control the solenoid actuator/valve,while the second channel (the passive channel) will be in an in-activemode ready to engage the solenoid if required.

Such conventional methods and systems have generally been consideredsatisfactory for their intended purpose. However, there is still a needin the art for systems and methods that allow for improved measurementof actuator/valve position. The present invention provides a solutionfor this need.

SUMMARY OF THE DISCLOSURE

The subject invention is directed to a new and useful system fordetecting the position of the dual solenoid device. The system includesa device configured to move between at least a first position and asecond position, and a controller. The controller has a first monitoringcircuit in operable communication with a first channel. The firstchannel is in operable communication with a first solenoid. Thecontroller includes a second monitoring circuit in operablecommunication with a second channel. The second channel is in operablecommunication with a second solenoid. Each solenoid is configured toselectively operate as an active solenoid to move the device when thesolenoid and the channel it is in operable communication with are in anactive mode. Each solenoid is configured to selectively operate as apassive solenoid when the solenoid and the channel it is in operablecommunication with are in a passive mode to passively move with theactive solenoid. Each of the monitoring circuits is configured todetermine a position of the device when the channel the monitoringcircuit is associated with is operating in the passive mode bymonitoring an electrical parameter of the passive solenoid associatedwith that channel.

Each channel can have a discrete switch associated with the controllerfor activating the channel. The first and second solenoids can bemechanically coupled to the device. It is contemplated that the devicecan be a valve and/or actuator.

In one embodiment of the subject invention, movement of the device fromthe first position to the second position is detected by monitoring thepresence of an induced voltage across the passive solenoid when thedevice is moving. The presence of the induced voltage across the passivesolenoid can be measured by a high speed analog/digital convertor.

In another embodiment of the subject invention, movement of the valve oractuator from the first position to the second position is detected bymonitoring a change in inductance in the passive solenoid. The change ininductance in the passive solenoid can be measured by applying an ACwaveform to the channel in operable communication with the passivesolenoid at a frequency and current level that will not engage thepassive solenoid. The frequency level of the AC waveform applied to thechannel in operable communication with the passive solenoid can be inthe range of about 3 to about 10 kH.

In accordance with another aspect, a method of determining the positionof a dual solenoid device includes designating one of a first channeland a second channel as an active channel and the other channel as apassive channel. Both channels are in operable communication with arespective solenoid. Each solenoid is in operable communication with adevice and configured to move the device in response to being the activechannel and to monitor a position of the device in response to being thepassive channel. The method includes determining the position of thedevice by monitoring an electrical parameter of the solenoid in operablecommunication with the passive channel.

In accordance with one embodiment, the solenoid in operablecommunication with the passive channel is a passive solenoid andmonitoring the electrical parameter of the passive solenoid includesmonitoring the presence of an induced voltage across the passivesolenoid. The method can include measuring the presence of an inducedvoltage across the passive solenoid with a high speed analog/digitalconvertor.

In accordance with another embodiment, the solenoid in operablecommunication with the passive channel is a passive solenoid. Monitoringthe electrical parameter of the passive solenoid comprises monitoring achange in inductance in the passive solenoid. Monitoring the change ininductance in the passive solenoid comprises applying an AC waveform toan associated channel at a frequency and current level that will notengage the passive solenoid.

In accordance with some embodiments, the device is device is at leastone of a valve or actuator. It is contemplated that the first and secondsolenoids can be mechanically coupled to the device, however, thoseskilled in the art will readily appreciate that mechanical coupling isnot required.

These and other features of the subject invention and the manner inwhich it is manufactured, assembled and employed will become morereadily apparent to those having ordinary skill in the art from thefollowing enabling detailed description of the preferred embodiments ofthe subject invention taken in conjunction with the several drawingsdescribed below.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those skilled in the art to which the subject inventionappertains will readily understand how to make and use the devices andmethods of the subject invention without undue experimentation,preferred embodiments thereof will be described in detail herein belowwith reference to certain figures, wherein:

FIG. 1 is a schematic representation of the position detection system ofthe subject invention wherein one of the channels is active such thatthe solenoid associated with the active channel is actively engaged withthe valve or actuator and the other channel is operating in a passivemode such that the solenoid associated with the passive channelpassively moves with the valve or actuator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings wherein like reference numerals identifysimilar structural elements or features of the prior art and the subjectinvention. For purposes of explanation and illustration, and notlimitation, a schematic depiction of an exemplary embodiment of aposition detection system constructed in accordance with the disclosureis shown in FIG. 1 and is designated generally by reference character100.

As shown in FIG. 1, there is illustrated the subject system 100 fordetecting the position of a device, such as a solenoid valve or actuator102, in aerospace applications and the like. Embodiments of the currentinvention will eliminate the need for the independent discrete switchesor sensors to determine solenoid position by utilizing the relationshipbetween the two solenoids in an active/passive configuration. System 100includes a device, for example, a valve or actuator 102, mounted in ahousing 101 for movement between a first positon and a second position.Those skilled in the art will readily appreciate that the first andsecond positions can be positions along longitudinal axis A. System 100also has a controller 104, a first channel 106 having a first solenoid108 coupled to the valve or actuator 102, and a second channel 110having a second solenoid 112 coupled to valve or actuator 102. First andsecond solenoids 108 and 112, respectively, are mechanically coupled tovalve or actuator 102. Those skilled in the art will readily appreciatethat a mechanical coupling is not required.

With continued reference to FIG. 1, each channel 106 and 110 of system100 selectively operates as an active channel in which solenoid 108 or112 associated therewith actively moves valve or actuator 102 betweenthe first position and the second position, or as a passive channel inwhich solenoid 108 or 112 associated therewith passively moves with thevalve or actuator 102 between the first position and the secondposition. Solenoid 108 or 112 associated with the active channeloperates as an active solenoid to move valve or actuator 102 in anactive mode. Solenoid 108 or 112 associated with the passive channeloperates as a passive solenoid to passively move with the activesolenoid. Each of channels 106 and 108 has a discrete switch 114 and115, respectively, associated with controller 104 for activating itsrespective channel 106 and 110. Controller 104 includes monitoringcircuits 116 and 118 associated with respective channels 106 and 110 forverifying the position of the valve or actuator 102 when theirrespective channel is operating as a passive channel, by monitoring anelectrical parameter of solenoid 108 or 112 associated with thatchannel. In FIG. 1, channel 106 is in active mode and is engaged as theactive channel and channel 110 is in passive mode, e.g. channel 110 isthe passive channel. In the active/passive configuration, active channel106 engages its respective solenoid 108, e.g. the active solenoid, andsolenoid 112, e.g. the passive solenoid, of passive channel 110 alsomoves. Two different electrical parameters of solenoid 112 of channel110 are then used to verify that the active channel's solenoid 108 hasmoved the valve/actuator 102.

As shown in FIG. 1, in one embodiment of the subject invention, movementof the valve or actuator 102 from the first position to the secondposition is detected by monitoring the presence of an induced voltageacross passive solenoid 112 associated with passive channel 110 whenvalve or actuator 102 is moving by using corresponding monitoringcircuit 118. It is contemplated that the presence of an induced voltageacross passive solenoid 112 associated with the passive channel 110 canbe measured by a high speed analog/digital convertor 120. Those skilledin the art will readily appreciate that for dynamic movement checks onecan record the voltage across the passive channels solenoid to check forthe presence of an induced voltage while the actuator/valve is moving.Those skilled in the art will also readily appreciate that channel 106can be the passive channel while channel 110 is active and solenoid 108associated with passive channel 106 can be the passive solenoid 108passively moved with the valve or actuator 102 between the firstposition and the second position.

With continued reference to FIG. 1, in another embodiment of the subjectinvention, movement of the valve or actuator 102 from the first positionto the second position is detected by monitoring a change in inductancein passive solenoid 112 associated with passive channel 110. Knowingthat the solenoid inductance may change as a function of the position ofvalve or actuator 102, one can measure the inductance of passivesolenoid 112 to determine the position of valve or actuator 102.Preferably, the change in inductance in passive solenoid 112 associatedwith the passive channel 110 is measured by applying an AC waveform topassive channel 110 at a frequency and current level that will notengage solenoid 112 associated with the passive channel 110. Thefrequency level of the AC waveform applied to passive channel 110 ispreferably in the range of about 3 to about 10 kH. The current wouldtypically range from about 100 uA to about 50 mA. Those skilled in theart will readily appreciate that this would be sized so as to be atleast twice the drop out current. Those skilled in the art will readilyappreciate that embodiments of the subject invention can providediscrete position measurements, continuously detect positionmeasurements, or a combination of both. The AC waveform can be suppliedto channels 110 and/or 112 by a digital-to-analog converter (DAC),field-programmable gate array (FPGA), oscillator through filter, and thelike. It is contemplated that the device supplying the waveform would beincluded in monitor circuits 116 and 118.

The methods and systems of the present disclosure, as described aboveand shown in the drawings, provide position detection systems withsuperior properties, including reduced weight and reduced harnesscomplexity. While the subject disclosure has been shown and describedwith reference to preferred embodiments, those skilled in the art willreadily appreciate that changes and/or modifications may be made theretowithout departing from the scope of the subject disclosure.

What is claimed is:
 1. A system for detecting a position of a dualsolenoid device, comprising: a device configured to move between atleast a first position and a second position; and a controller having afirst monitoring circuit in operable communication with a first channel,wherein the first channel is in operable communication with a firstsolenoid, and wherein the controller includes a second monitoringcircuit in operable communication with a second channel, wherein thesecond channel is in operable communication with a second solenoid,wherein each solenoid is configured to selectively operate as an activesolenoid to move the device when the solenoid and the channel it is inoperable communication with are in an active mode, wherein each solenoidis configured to selectively operate as a passive solenoid when thesolenoid and the channel it is in operable communication with are in apassive mode to passively move with the active solenoid, each of themonitoring circuits being configured to determine a position of thedevice when the channel the monitoring circuit is associated with isoperating in the passive mode by monitoring an electrical parameter ofthe passive solenoid associated with that channel.
 2. A system asrecited in claim 1, wherein movement of the device from the firstposition to the second position is detected by monitoring the presenceof an induced voltage across the passive solenoid when the device ismoving.
 3. A system as recited in claim 2, wherein the presence of theinduced voltage across the passive solenoid is measured by a high speedanalog/digital convertor.
 4. A system as recited in claim 1, whereinmovement of the device from the first position to the second position isdetected by monitoring a change in inductance in the passive solenoid.5. A system as recited in claim 4, wherein the change in inductance inthe passive solenoid is measured by applying an AC waveform to thechannel in operable communication with the passive solenoid at afrequency and current level that will not engage the passive solenoid.6. A system as recited in claim 5, wherein the frequency level of the ACwaveform applied to the channel in operable communication with thepassive solenoid ranges from 3 to 10 kH.
 7. A system as recited in claim1, wherein the first and second solenoids are mechanically coupled tothe device.
 8. A system as recited in claim 1, wherein each channel hasa discrete switch associated with the controller for activating thechannel.
 9. A system as recited in claim 1, wherein the device is atleast one of a valve or actuator.
 10. A method of determining a positionof a dual solenoid device comprising: designating one of a first channeland a second channel as an active channel and the other channel as apassive channel, both channels being in operable communication with arespective solenoid, wherein each solenoid is in operable communicationwith a device and configured to move the device in response to being theactive channel and to monitor a position of the device in response tobeing the passive channel; and determining the position of the device bymonitoring an electrical parameter of the solenoid in operablecommunication with the passive channel.
 11. A method as recited in claim10, wherein the solenoid in operable communication with the passivechannel is a passive solenoid, wherein monitoring the electricalparameter of the passive solenoid comprises monitoring the presence ofan induced voltage across the passive solenoid.
 12. A method as recitedin claim 11, further comprising measuring the presence of an inducedvoltage across the passive solenoid with a high speed analog/digitalconvertor.
 13. A method as recited in claim 10, wherein the solenoid inoperable communication with the passive channel is a passive solenoid,wherein monitoring the electrical parameter of the passive solenoidcomprises monitoring a change in inductance in the passive solenoid. 14.A method as recited in claim 13, wherein monitoring the change ininductance in the passive solenoid comprises applying an AC waveform toan associated channel at a frequency and current level that will notengage the passive solenoid.
 15. A method as recited in claim 10,wherein the device is at least one of a valve or actuator.